Climate Change Impacts On Seasonal Rainfall Trends in the Regions of Andhra Pradesh and Telangana States, India

Climate change significantly affects the hydrologic process and consequently the availability of water resources in a region. In certain regions, it may cause large variations in rainfall with occurrence of extreme rainfall events that result in either floods or droughts. In the rapid climate change scenario, it is therefore pertinent to study regional rainfall trends and corresponding trends of other climatic variables for optimal and sustainable utilization of water resources of a region. The present study focuses on climate variability and its impact on seasonal and annual rainfall trends in the regions of Andhra Pradesh and Telangana states, India. Daily rainfall data along with relative humidity, temperature, vapour pressure and wind speed at Anantapur, Arogyavaram and Kurnool located in Rayalaseema region, Kakinada, Machilipatnam and Nellore in Coastal region of Andhra Pradesh state and, Hyderabad, Nizamabad and Ramagundam of Telangana state, collected for the period 1969–2008 from India Meteorological Department (IMD) Pune, were used in the analysis. Trend analysis of seasonal (monsoon and post-monsoon) and annual rainfall and other climatic parameters indicated an increase in rainfall with an increase in relative humidity, vapour pressure and temperature and a decrease in wind speed. An increase in annual rainfall of 7.4 mm/year at Kurnool may be due to increase in relative humidity by 0.093%/year and temperature by 0.016 °C/year . Monsoon and annual rainfall increased by 6.04 mm/year and 4.96 mm/year at Kakinada and Machilipatnam, respectively, due to respective increase in vapour pressure by 0.019 mbar/year and 0.38 mbar/year. Increase in relative humidity by 0.07%/year and vapour pressure by 0.058 mbar/year at Hyderabad of Telangana state showed a significant increase in annual rainfall of 10.92 mm/year. The climate variability at the stations in the regions reported in the present study may be helpful in the assessment of seasonal/annual rainfall in the regions.